Re: [dpdk-dev] [PATCH 3/4] net/mlx5: rework PMD global data init

[Yongseok Koh <yskoh@mellanox.com>]

On Thu, Mar 14, 2019 at 05:36:28AM -0700, Shahaf Shuler wrote:
> Hi Koh,
> 
> Thursday, March 7, 2019 9:33 AM, Yongseok Koh:
> > Subject: [PATCH 3/4] net/mlx5: rework PMD global data init
> > 
> > There's more need to have PMD global data structure. It should be initialized
> > once per a process regardless of how many PMD instances are probed.
> > mlx5_init_once() is called during probing and make sure all the init functions
> > are called once per a process. The existing shared memory gets more
> > extensively used for this purpose. As there could be multiple secondary
> > processes, a static storage (local to process) is also added.
> 
> It is hard to understand from the commit log what was missing on the old design. 

Okay, will add more comments.

> > As the reserved virtual address for UAR remap is a PMD global resource, this
> > doesn't need to be stored in the device priv structure, but in the PMD global
> > data.
> 
> I thought we agreed to drop those and have different VA for each process. 
> If so, is the extra work on the UAR here is needed? 

My plan was to do that in a separate patch for performance regression.
Let me know if you want it to be done in this patchset.

> > Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> > ---
> >  drivers/net/mlx5/mlx5.c     | 250 ++++++++++++++++++++++++++++++++--
> > ----------
> >  drivers/net/mlx5/mlx5.h     |  19 +++-
> >  drivers/net/mlx5/mlx5_mp.c  |  19 +++-
> >  drivers/net/mlx5/mlx5_txq.c |   7 +-
> >  4 files changed, 217 insertions(+), 78 deletions(-)
> > 
> > diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index
> > 6ed2418106..ea8fd55ee6 100644
> > --- a/drivers/net/mlx5/mlx5.c
> > +++ b/drivers/net/mlx5/mlx5.c
> > @@ -128,16 +128,26 @@ struct mlx5_shared_data *mlx5_shared_data;
> >  /* Spinlock for mlx5_shared_data allocation. */  static rte_spinlock_t
> > mlx5_shared_data_lock = RTE_SPINLOCK_INITIALIZER;
> > 
> > +/* Process local data for secondary processes. */ static struct
> > +mlx5_local_data mlx5_local_data;
> 
> Why not storing this context as part of ethdev-> process_private instead of declaring it static? 

Because it is not per-device data but per-PMD data.

Will also have to rebase my patchsets when I send out v2.


Thanks,
Yongseok